The present invention relates to a digitizer of the type having a flat tablet operative to electromagnetically or magnetically detect a given point thereon inputted by means of a pointing tool so as to designate a two-dimensional coordinate value to the given point to thereby effect digitization of inputted graphic information.
In the conventional digitizer of this type, the tablet has a flat electromagnetic or magnetic sensor, and a shield plate is disposed under the flat sensor to block incidental disturbing electromagnetic waves or geomagnetism, which would affect sensitivity of the flat sensor.
However, in the conventional structure, if the flat sensor and the shield plate are disposed too close to each other, the magnitude level of detection signal produced by the flat sensor is reduced to thereby hamper the effective detection of inputted points. Thus, the conventional structure has the drawback that the total thickness of the tablet cannot be minimized because they must be spaced from each other.